Warmup

Given a  and b are numbers, and a + b = 180, which statements also must be true?

Activity #1

Identify Angles. • Use any useful tools in the geometry toolkit of the applet below to identify any pairs of angles.

(1.) Name a pair of the following angles;

(a.) Complementary angles.

(b.) Supplementary angles.

• Use a straightedge to draw two intersecting lines.
• Use a protractor to measure all four angles whose vertex is located at the intersection.

(2.) Make a conjecture about the relationships between angle measures at an intersection.

Activity #2

Find Missing angles. • Pull the sliders to the right.
• Find the measure of the angles in column A and column B and enter your values in the box. You may have to click and drag the applet to see off-screen portions.

Challenge #1

The two lines below intersect. Find the value of  b and c.

(1.) Angle b = ?

(2.) Angle c = ?

Challenge #2

In the figure above, angles R and S are complementary.

(1.) Find the measure of angle S.

(2.) If two angles are both vertical and supplementary, can we determine the angles? Is it possible to be both vertical and complementary?

(3.) If so, can you determine the angles? Explain how you know.

Quiz Time